Types of water heater or geyser available in market

Geyser or water heater is a commonly used home appliance. It produces hot water that we use for various purposes like bathing, cleaning, washing etc. Water heating is a simple thermodynamic process where a source of energy like electricity, natural gas or solar energy heats the water.

Broadly there are two types of water heater or geyser available in Indian market :

1. Tank-type water heater
2. Tank-less water heater

Tank-type or storage tank water heater

As the name suggests tank type geyser or heater has a storage tank to reserve hot water. Tank type geyser maintains the temperature of hot water within the storage tank with the help of an automatic thermal control. The heating element switches on-off periodically to maintain the temperature of water in the storage tank.

Pros of tank-type water heater

• Tank type water heater has a lower initial purchase price.
• Tank type water heater has low energy requirement

Cons of tank-type water heater

• A tank type water heater is less energy efficient than a tank-less water heater.
• Once all of the available water stored in the  tank is used, it takes time to heat more water.
• The freshness and quality of water is sometime compromised. The water you use sits in a tank with corrosion and rust.
• Storage tank of the heater takes up much more floor space.
• The sediment dissolved in water may corrode/damage the inner protection of tank wall and may cause tank leakage problem.

Tank-less water heater

A tank-less water heater does not have a storage tank.  It is a like a small rectangular box mounted on the wall, that carries a burner or heating element, thermal control knobs, and internal piping. The water heater only starts when there is a need for hot water. When tap or shower is turned on, water starts flowing through the heater pipes. The heating sensor senses the water flow, which in turn fires the burner or heating element thereby producing hot water for consumption. It is available in electric as well as natural gas models.

Pros of tank-less water heater

• Tank-less water heater requires less space as there is no storage tank
• It never runs out of hot water.
• Tank-less heater have a longer life compared to tank-type heater
• It uses energy only when it is required.
• It is more energy efficient than tank-type heater.

Cons of tank-less water heater

• Tank-less type water heater are costly.
• It has a large power/gas requirement.